Not Applicable
Not Applicable
1. Fields of the Invention
The present invention relates generally to apparatuses and methods of combining the multiple laser beams of multiple laser sources wherein the beam combiner is mounted in a laser material processing platform, and, more particularly, to combining pre-aligned multiple laser beams of multiple laser sources each of which is independently interfaced with a pre-aligned optical axis of a beam delivery system of the laser material processing platform.
2. Discussion of Background and Prior Art
In our co-pending application entitled Method And Apparatus For Making Laser Sources and Laser Platforms Interchangeable and Interfaceable, which is hereby incorporated herein by reference, we described a pre-alignment apparatus and method in which each pre-aligned laser source of a line is interchangeable with any other laser source in the line similarly pre-aligned, each pre-aligned laser material processing platform in a line is interchangeable with any other laser material processing platform in the line similarly pre-aligned, and any such laser source is independently interfaceable with any such laser material processing platform, the respective beam paths and optical axes of any such laser source and any such laser material processing platform coinciding when any such laser source in the line is combined with any such laser material processing platform in the line to form a laser material processing system.
In an apparatus by Synrad, Inc. of Bothell Wash. 98011 a laser source Model 48-5-28 combines two standard, sealed off laser tubes to obtain twice the power of a single laser tube. The output beams from two 25 watt sealed off CO2 tubes are combined optically to provide a single, diffraction-limited beam at 50 watts. Series 48 Lasers. Operation and Service Manual, Release v2.0, Synrad, Inc. (Oct. 18, 1995), p.15. All power and control functions between the two laser sections are totally independent, essentially achieving fail-safe operation for applications that can be served with the power of one laser. Any one electronic or laser tube failure will only affect that section, leaving the second channel unaffected and available for temporary use. The optical combining technique is based on the fact that each laser is linearly polarized, allowing the use of a polarization sensitive beam combiner to achieve 98% efficiency in combining the two beams. The two components of the resulting beam are spatially parallel and colinear. The normal temporal and spatial variations of a single laser are reduced by combining the output of two lasers. Output polarization is random. The 2-in-1 laser source is self-contained requiring only the application of power, cooling water, and a control signal.
There are several problems with the Synrad 2-in-1 concept:
1. If one tube fails, the whole dual laser assembly must be replaced.
2. There is no ability to reconfigure the laser system in the field to mix power levels of various laser sources to match a particular application.
3. The customer cannot buy just one laser source now and add another later.
Accordingly, it is an object of the present invention to provide a laser material processing platform into which one or more laser sources may be independently mounted to form a laser material processing system which can be rapidly reconfigured to match the specific power level requirements of any application.
In a prior apparatus and method by Morrow in U.S. Pat. No. 4,982,166 there is disclosed two independent lasers A and B mounted on a rigid base plate K upon which is also disposed a mixer box G. Adjustable optical element E is mounted in mixer box G presenting one of its optical surfaces at a Brewster angle relative to laser beam A and has a thin film polarizer coating on its other optical surface. Adjustable mirror H is also mounted in mixer box G and reflects 100% of laser beam B onto the coated surface of element E whereby 100% of beam A is transmitted by element E and substantially all of beam B is reflected by element E and the output is a common colinear beam with a power level that is approximately the sum of the power levels of the individual beams which is useful for medical treatment.
There are several problems with the Morrow apparatus.
1. There is no disclosure of beam combining optical elements separately mounted on a laser material processing platform with a beam delivery system with which the outputs of the dual lasers cooperate to do work on a workpiece, and because the beams may not be aligned well on the disclosed base plate even after installation and alignment, the patented structure seems limited in use to primarily manually articulated medical applications where small misalignments are not a major problem.
2. While Morrow""s independent mounting on a base plate of the lasers allows him some flexibility in substituting lasers, nevertheless, as in Synrad""s case, because the laser beams are not pre-aligned to a predetermined reference, Morrow""s dual laser source structure cannot be rapidly reconfigured in the field to mix power levels of various laser sources to match a particular application without the need for a further alignment procedure.
Accordingly, it is an object of the present invention to provide a host laser material processing platform having a beam delivery system the optical axis of which is independently interfaced with the beam paths of multiple laser sources which are made colinear through a combiner mounted in the host laser material processing platform.
It is a further object of the present invention to enable a laser material processing system which can be controlled automatically by a computer program, and, in which, optionally, the laser beam paths and beam delivery system optical axis are each separately pre-aligned to a predetermined reference thereby making said components rapidly and interchangeably interfaceable.
Set forth below is a brief summary of the invention which achieves the foregoing and other objects and provides the foregoing and hereafter stated benefits and advantages in accordance with the structure, function and results of the present invention as embodied and broadly described herein. Applicants"" invention includes independently both the apparatus and the methods described herein which achieve the objects and benefits of the present invention. Both formats of the invention are described below, and it is applicants"" intention to claim both formats even though from time to time below for purposes of clarity and brevity applicants will use either one or the other format to describe various aspects and features of the invention.
A first aspect of the invention is a laser material processing platform which includes a housing for supporting a workpiece on a work surface, a combiner having one or more optical elements mounted in the housing for making beams of multiple laser sources parallel and colinear, and a beam delivery system supported in the housing for directing the laser beam paths to the workpiece.
Further features of this aspect of the invention include a computer for controlling the performance of the work on the workpiece in response to a work program, the beam delivery system having an optical axis which has been pre-aligned to a predetermined reference, the combiner including an optical element having optical surfaces that are transmissive to one beam and reflective of another beam or an optical element having optical surfaces that are transmissive to a beam of one polarization state and reflective of a beam of another polarization state or an optical element oriented at a Brewster angle relative to a laser beam, and the combined laser beams movable in X-Y planes in the laser material processing platform relative to the workpiece supportable therein.
A second aspect of the invention is a method of making a laser material processing platform which includes the steps of mounting one or more optical elements on a housing for combining multiple laser beams to make the beam paths parallel and colinear, and mounting a beam delivery system in the housing for directing the combined laser beams to a workpiece supportable on a work surface therein for performing work thereon.
Further features of this aspect of the invention are the same as those set forth above as to the first aspect of the invention and are incorporated herein by reference.
A third aspect of the invention is a laser material processing system which includes a laser material processing platform for supporting a workpiece on a work surface, one or more laser sources supported in the laser material processing platform each providing a laser beam path, a beam delivery system having an optical axis supported in the laser material processing platform for directing the laser beam paths to the workpiece, and a combiner having one or more optical elements mounted on the laser material processing platform for making the beam paths parallel and colinear.
Further features of this aspect of the invention include the beam path of each laser source is independently interfaced with the optical axis of the beam delivery system, each laser source is independently supported on a separate mounting member on the laser material processing platform, each laser source is one in a line of which all are pre-aligned to a predetermined reference and the optical axis of the beam delivery system of the laser material processing platform is one in a line all of which are pre-aligned to the same predetermined reference as the laser sources so that the beam paths and optical axis automatically coincide upon mounting the laser sources on their respective mounting members, and each laser source is interchangeable with any laser source in the line.
Further features of this aspect of the invention are the same as those set forth above as to the first aspect of the invention and are incorporated herein by reference.
A fourth aspect of the invention is a method of making a laser material processing system which includes the steps of providing a laser beam path from each of one or more laser sources supported in a laser material processing platform, combining the laser beams through one or more optical elements mounted on the laser material processing platform to make the beam paths parallel and colinear, and directing the combined laser beams through a beam delivery system supported on the laser material processing platform for performing work on a workpiece supportable on a work surface therein.
Further features of this aspect of the invention are the same as those set forth above as to the first and third aspects of the invention and are incorporated herein by reference.
The advantages of the invention include the following:
1. Because the combiner optical elements are separately mounted on a laser material processing platform with a beam delivery system with which the outputs of the multiple lasers cooperate, the ability to use a laser to perform a broad spectrum of useful functions in a precision manner on a wide variety of materials is substantially enhanced.
2. Any laser system can be rapidly reconfigured in the field to mix power levels of various laser sources to match a particular application without the need for further alignment.
3. More efficient use of invested capital. Buy only the laser source you currently need and can afford and get an additional slot in the laser platform ready to receive the next laser source when it is needed as the business grows.
4. Substantially increased flexibility in customizing laser sources and laser material processing systems to match material processing requirements.
5. Add new laser sources to a line and satisfy multiple needs with one purchase.
6. Expanded utility of capital equipment without adding new equipment.
7. Optimized laser performance on the workpiece.
8. Reduced setup costs.
9. Decreased down time.
10. Enhanced productivity.
11. Increased profit-making opportunities.